Ideally, computer users wish to have their color displays delivered already calibrated so that displayed colors are consistent with accepted industry standards. Due, however, to variations in display apparatus and operating systems, display-to-display color matching and display-to-printer color matching is often not achieved on initially delivered products.
Systems for calibrating color-display characteristics are known in the prior art. Such systems embody "active" hardware calibrators, "passive" software calibrators and "active" software calibrators. Active calibrators actually change a display's characteristics to a known viewing state, depending upon a user's perception of differences between displayed standard color patches and a variable color patch. Active calibrators are both embodied in software and hardware, with hardware calibrators making use of a sensor that is attached to the screen of the display and enables feedback of correction information to the display. Passive software calibrators detect the characteristics of a color displayed on a screen (through user-interaction) and pass this information to other system components to enable color matching.
Both active and passive software display calibrators rely upon a user's ability to perceive a color match on a screen and to respond in such a manner that the computer which controls the display system is able to arrive at a correction factor. Because these systems depend upon a user's visual acuity and an ability to follow instructions, obtained calibration values are, in many cases, at variance with an accurate calibration value. Accurate calibration of a color display is important when it is desired to have a color printer faithfully reproduce a color image shown on the display. Larger differences in color values between the display and the printer are unacceptable to the discerning user.
While it has been found that user problems in implementing a software-based calibration procedure can be overcome by presenting the user with additional test patterns and repetitions of a calibration procedure, such is not acceptable due to the time demands made on the user--who is much more interested in actually using the the screen.
Accordingly, it is an object of this invention to provide an improved software system for calibrating a color display.
It is another object of this invention to provide a system for calibrating a color display which reacts to a user's error by substituting a default calibration value.
It is yet another object of this invention to provide an improved passive software calibrator that enables color matching of a computer display with colors presented by an attached color printer.